THE MYSTERY THAT NEVER WAS (FREE DELIVERY)
Nick and Katie and their neighbours, Mike and Penny, are enjoying the end of the summer holidays. When Uncle Bob comes to stay for a rest, he seems a bit bored without his exciting private investigator's job to do, so the children invent a mystery for him to solve. But life soon becomes very exciting when cracking the children's code leads to a real-life mystery with serious consequences.